Lubrication controls for valve stems of modern internal combustion engines, which operate in hot, oil-saturated environments, are required to allow only limited lubrication to pass along the stems as they reciprocate thousands of times per minute in their guides. The control materials in movable contact with the valve stems must be resistant to fuels, oils and gases, and heat sometimes above 300.degree. F. (149.degree. C.), as well as aging and wear. This dictates the use of relatively sophisticated and expensive elastomers, such as polyacrilates, silicone rubbers, fluoroelastomers and the like.